Here’s what’s up in the world of TV for Wednesday, April 12. All times are Eastern.

Top Pick

Underground (8 p.m., WGN): If you’re going to highlight Harriet Tubman in your series, you better give her something as iconic and unusual as befits her extraordinary life. It’s a bit trite to say “if you’ve never seen Underground, this is the one to watch,” but from all accounts, this is an incredibly special episode, indeed. (Not a Very Special Episode, that’s something else.) “When introducing someone as iconic as Harriet Tubman, we felt compelled to attempt an episode as revolutionary as her spirit,” series creators Misha Green and Joe Pokaski said in a statement announcing the episode. “When we learned through research that in 1858 she began to give talks about her life to like-minded abolitionists to raise money for the cause, we knew we had our in—A ‘Ted Talk’ with Harriet Tubman.” Double-check your DVRs now—the special 68-minute episode airs earlier than usual.

Regular coverage:

Wild card

Bad Milo! (8 p.m., Chiller): After a long day of work, why not come home, kick off your shoes, crack open a cold beer, and watch a movie about a guy who has a murderous demon that lives in his colon and comes out to kill when he gets too stressed? A throwback to the rubbery-puppet horror of the ’80s, the film stars Ken Marino as the exasperated guy who slowly comes to realize his vengeful little butt-monster can’t be controlled. Equally cuddly and gross, the creature is a treat, and despite some wobbly parts, the movie that surrounds it is a decent entry in the ridiculous-horror genre.